He said David Cameron was conning voters by ditching ideals to move to the centre ground.

The ad guru, party co-chairman until last year, said in a lecture: "The centre ground has ground ideology out of politics.

"As one student said during the election, 'They just tell you what you want to hear'." The peer, who created Maggie Thatcher's famous 1979 election ads, said it was turning people off politics.

Meanwhile, John Reid claimed Mr Cameron's call to hug yobs proved he was out of touch. The Home Secretary said: "Nobody who takes the view he takes has any real experience of life as lived by the vast majority."